Hydraulic support prop



5 Sheets-Sheet 1 IN VEN TORS J- LE W/S THOMPSON WA RRE N A T TORNE Y Oct. 25, 1966 w. J. LEWIS ETAL HYDRAULIC SUPPORT PROP Filed Dec. 27, 1965 JOSEPH 3.

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Oct. 25, 1966 w. .1. LEWIS ETAL 3,281,108

HYDRAULI C SUPPORT PROP Filed Dec. 27, 1965 5 Sheets-Sheet 2 IIIIII INVENTORS WARREN J. LEW/S JOSEPH S. THOMPSON l wmwm ATTORNEY W. J. LEWIS ETAL HYDRAULIC SUPPORT PROP Oct. 25, 1966 5 Sheets-Sheet 5 Filed Dec. 27, 1965 INVENTOR5 WARREN J. LEW/S S. THOMPSON BY JOSEPH Wm M A T TORNE Y United States Patent 3,281,108 HYDRAULIC SUPPORT PROP Warren J. Lewis, Mansfield, and Joseph S. Thompson, Shelby, Ohio, assignors to The Ohio Brass Company, Mansfield, Ohio, a corporation of New Jersey Filed Dec. 27, 1965, Ser. No. 516,539 10 Claims. (Cl. 248-354) This invention relates to supports for mine roofs and, more particularly, to an extensible hydraulic prop therefor.

A principal object of the invention is to provide a portable light weight device useful for temporary support of roofs, floors, and the like.

Another object of the invention is to provide a hydraulic support prop for mine roofs which will accommodate substantial shifting and settling of the roof and which will distribute the load over a plurality of similar devices.

Still another object of the invention is to provide a self-contained hydraulic support prop which is adapted for manufacture and assembly from standard shapes and component parts.

The invention relates to a telescoping \hydraulic support prop for mine roofs and the like, in which the hydraulic system is entirely contained in the prop. This is accomplished by utilizing an elastic diaphragm in the top cylinder of the prop to constitute a fixed volume hydraulic system in the variable volume mechanical system of the prop. There is combined therewith a new arrangement of a release valve particularly adapted for automatic operation to relieve excess pressure in the hydraulic system of the prop, as might be caused by a subsiding mine roof, and for manual operation to collapse the prop and withdraw it from a remote or inaccessible working position.

Manufacture of the prop is facilitated by the use of standard tubular sections and O-r-ing seals.

The support prop of the invention will be more clearly understood by reference to the following detailed specification and claims, taken in connection with the appended drawings in which:

FIG. 1 is a vertical sectional view of the hydraulic support prop of the invention;

FIG. 2 is a transverse sectional view, taken along the line 22 in FIG. 1, showing the arrangement of the bypass valves;

FIG. 3 is a transverse sectional view, taken along the line 33 in FIG. 1, showing the arrangement of the release valve;

FIG. 4 is a transverse sectional view, taken along the line 4-4 in FIG. 1, showing details of the hydraulic pump; and

FIG. 5 is an enlarged view of the upper cylinder of the prop.

The support prop comprises a base 11, a base cylinder 12, a base head 13, a top cylinder 14, a top head 15, and a cross head 16 at the lower extremity of the top cylinder 14. A pump 17 functions to transfer bydraulic fluid from the top cylinder 14 through a stand pipe 18 to the interior of the cylinder 12. A release valve 19 functions to return hydraulic fluid from the cylinder 12, through the stand pipe 18, to the cylinder 14 by manual operation of the valve or to relieve an over-pressure on the interior of the base cylinder 12.

The base 11 comprises a base plate 21 and a cylindric metal tube 22 welded to the top side of the plate 21. The base head 13 comprises a metal body 23 which has a recessed lower extremity received in the base tube 22 and a recessed upper extremity received in the cylindric metal tube 24 which comprises the base cylinder "ice secured to it by a press fit and an O-ring 26 or, alternately, by welding and brazing.

A collar 27 is secured to the top end of the cylinder tube 24 by suitable means (not shown) adapted for removal of the collar and the cylinder 14. A ring seal 28 is received in a groove on the interior periphery of the collar 27 and engages the exterior surface of a cylindric metal tube 29 to seal the joint between the base cylinder 12 and the top cylinder 14.

The top head 15 is constituted as a cylindric metal body 30 having a recessed lower extremity received in the top cylinder tube 29. The body 30 has a spherical recess 31 in the outward face thereof for engaging a roof plate or other member and a ring 32 comprising an attachment means for the top cylinder. A plug 33 is provided for filling or emptying the cylinder with hydraulic fluid.

The cross head 16 comprises a cylindric metal body 34 having a recessed top extremity received in the top cylinder tube 29. Two ring seals 35 and 36 are received in peripherally extending grooves and engage the interior wall of the lower cylinder tube 24 to seal the joint between the base cylinder 12 and the top cylinder 14. The stand pipe 18 extends through an opening 37 centrally through the body 34, and a ring seal 38 is received in a circumferential interior groove in the body 34 and engaged with the exterior surface of the stand pipe 18 to seal the joint between the stand pipe and cross head. By-pass valves 39, comprising valve balls and springs received in and cooperating with valve openings 40 in the body 34, are arranged to respond to a pressure differential between the cylinders 14 and 12. The cylinder 14 is extended with respect to the cylinder 12 by drawing the cylinders apart with a force sufficient to open the valves 39 and permit fluid movement from the cylinder 14 to the cylinder 12. Other forms of by-pass valves useful in the practice of the invention are described in application Serial No. 514,090, filed December 15, 1965, by Warren J. Lewis, now Patent No. 3,281,107, granted October 25, 1966.

The pump 17 is constituted by a pump cylinder 42 received in a transverse opening 43 in the body 23, a piston 44 received in an opening 45 in the cylinder 42, an intake valve 46, and an exhaust valve 47. The intake valve 46 is connected from the piston opening 45 to the stand pipe 18 by an axial opening 48 and cross openings 49 in the body of the piston 44, a space 50 between the cylinder 42 and piston 44, defined by O-rings 51 and 52, a transverse opening 53 in the cylinder 42, the opening 43 between the cylinder 42, the body 23, and the O-rings 54 and 55, comprising the space 56, and a longitudinal opening 57 in the body 23 communieating with the interior opening of the stand pipe 18. The exhaust valve 47 is connected from the piston opening 45 through the cylinder 42 to the space 58 between the cylinder 42 and the body 23, defined by the O-ring 55, and a longitudinal opening 59 in the body 23. Accordingly, alternating transverse movement of the piston 44 draws hydraulic fluid from the space 60 in the top cylinder and drives the hydraulic fluid into the space 61 in the base cylinder 12.

The pump 17 includes a handle 63 which is connected to the piston 44 by a pin 64. The handle is supported from the body 23 by the piston 44 and by a plug 65 threaded in the body, a connecting link 66, and two pins 67 and 68.

The release valve 19 comprises a slide or piston 70 received in an opening 71 extending transversely'in the body 23 of the base head. A spring 72 extends between the inner extremity of the threaded plug 65, which is received in the opening 71, and the piston 70 and holds the piston 70 in a normally closed position with the land 73 engaged with the shoulder 74. The shoulder 74 defines an opening 75 of reduced diameter with respect to the opening 76 in which the spring 72 and the land 73 are received. A land 77 of the piston 70, of reduced diameter with respect to the land 73, is engaged with the shoulder 78 which defines an opening 79 of reduced diameter with respect to the opening 75. The opening 71 is closed by an O-ring extending peripherally about the land 77 in a groove formed on the exterior periphery thereof, engaged with the interior surface of the shoulder 78.

The opening 71 extends transversely through the body 23 and intersects the longitudinal openings 57 and 59 so that fluid communication is provided between the stand pipe 18 and cylinder 12 through the openings 75 and 76 thereof. Because of the difference in diameters of the land 73 and the land 77, the differential of force is directed radially inward against the spring 72, so that the piston 70 moves inward upon the occurrence of a predetermined over-pressure in the cylinder 12. Opening movement of the piston 70 allows the hydraulic fluid to flow from the cylinder 12, through the opening 59, the openings 76 and 74, the opening 57, and the stand pipe 18, to the cylinder 14.

A handle 82, for manual operation of the piston 70, is carried by laterally spaced guard members 83, welded to the side of the body 13, and is pivoted upon a pin 84. The interior extremity of the handle 82 is shaped as a cam so that rotation of the handle 82 moves the piston 70 in or out to open or close the relief valve. The guard members 83 extend outwardly from the body 23 and are spaced from the cylinder tube 24 to protect the valve handle 82.

The top cylinder 14 is provided with a diaphragm 86 constituted by a tubular elastic member 87 extending along the interior of the upper cylinder tube 29 and received over the extremities of the bodies 30 and 34. The cylinder 29 is assembled with the bodies 30 and 34 by a press fit over the body along a peripheral recess thereof, and the elastic member 87 is compressed between the cylinder tube 29 and the bodies 30 and 34 to retain the member in place in the cylinder tube. O-rings 88 are compressively received between the member 87 and the cylinder tube 29, although not essential to the practice of the invention. Set screws or the like may be utilized for compressively securing the cylinder tube 29 to the bodies 30 and 34 and the collar 27 to the cylinder tube 24.

Openings 89 through the walls of the cylinder tube 29 permit flow of atmospheric air into the space 90 between the diaphragm 86 and the tube 29. Accordingly, the diaphragm 86 expands and contracts with movement of the top cylinder 14 in the base cylinder 12 to maintain a constant volume in the hydraulic system and constant fluid pressure in the top cylinder.

It is a feature of the prop that it may be retrieved from an inaccessible working position in a mine by means of a rope extending from the valve handle 82 through the ring 32 to a remote point. Pulling the rope ro tates the handle 82, opens the valve 19 to release hydraulic fluid from the base cylinder 12 to the top cylinder 14 and retracts the top cylinder 14 into the base cylinder 12, so that the entire prop may be towed from the inaccessible position and re-used.

The diaphragm 86 and the various ring seals are made of natural rubber, neoprene, or other elastomeric materials selected for properties of elasticity, resistance to deterioration by the hydraulic fluid, and resistance to abrasion. The diaphragm member 87 is advantageously fabricated from standard tubular materials of uniform cross section throughout the length thereof.

The hydraulic support prop is useful when inverted from the positions shown in the drawings. Accordingly, it is to be understood that the specific terminology of the description and of the claims does not restrict or limit the QP? 9f the invention. The claims are directed to combinations of elements which embody the invention or inventions of the application.

We claim:

1. A hydraulic device comprising a base and a base head, a base cylinder on the base head, a top cylinder telescoping into the base cylinder at the end thereof away from the base, a top head on the top cylinder at the end thereof away from the base, a cross head on the top cylinder at the end thereof adjacent the base, a stand pipe extending from the base head axially through the base cylinder and cross head into the top cylinder, the stand pipe providing fluid communication between the base and the interior of the top cylinder, fluid sealing means between the base cylinder and the top cylinder and between the cross head and the stand pipe, hydraulic fluid storage means on the interior of the top cylinder constituted by a tubular elastic diaphragm extending between the top head and the cross head and extending peripherally about the longitudinal axis of the top cylinder and the stand pipe, and means in the base head connecting the stand pipe with the inlet of the pump means, conduit means connecting the outlet of the pump means to the interior of the base cylinder, all for transmitting hydraulic fluid between the base cylinder and the storage means.

2. A hydraulic device in accordance with claim 1 with by-pass valve means in the cross head responsive to an excess pressure in the top cylinder for transmitting hydraulic fluid from the storage means to the base cylinder.

3. A hydraulic device in accordance with claim 1, in which the top cylinder comprises a cylindric metal tube with the top head and cross head received in the ends thereof, and the diaphragm comprising a generally cylindric member compressively received between the cylinder tube and the two heads for defining a fluid-tight space on the interior of the diaphragm member.

4. A hydraulic support prop comprising a base and a base head, a base cylinder on the base head, a top cylinder telescoping into the base cylinder at the end thereof away from the base, a top head on the top cylinder at the end thereof away from the base, a cross head on the top cylinder at the end thereof adjacent the base, a stand pipe extending from the base head axially through the base cylinder and cross head into the head cylinder, the stand pipe providing fluid communication between the base and the interior of the head cylinder, fluid sealing means between the base cylinder and the top cylinder and between the cross head and the stand pipe, hydraulic fluid storage means on the interior of the top cylinder constituted by a tubular elastic diaphragm extending between the top head and the cross head and extending peripherally about the longitudinal axis of the top cylinder and the stand pipe, hydraulic pump means in the base head, conduit means connecting the stand pipe with the inlet of the pump means, conduit means con necting the outlet of the pump means to the interior of the base cylinder, all for containing hydraulic fluid in the base cylinder and storage means and operatively extending the head and head cylinder with respect to the base and base cylinder by actuation of the pump means.

5. A hydraulic prop in accordance with claim 4, with openings thnough the walls of the top cylinder for maintaining the pressure on the exterior surface of the diaphragm at the pressure of the atmosphere about the prop.

6. A hydraulic prop in accordance with claim 4, with a release valve in the base connecting the named two conduit means for relieving fluid pressure in the base cylinder by transmitting hydraulic fluid from the base cylinder through the stand pipe to the top cylinder.

7. A hydraulic prop in accordance with claim 6, in which the release valve comprises a transverse bore in the base head, a piston in the transverse opening having two lands of differing diameter engaged with shoulders spaced along the interior of the opening, and spring means holding the lands in fluid-tight engagement with the shoulders, a conduit from the transverse opening between the said shoulders to the base cylinder normally communicating therewith, and conduit means from the trans verse opening to the stand pipe and normally closed by the said piston and being connected with the firstnamed longitudinal opening upon movement of the piston in the transverse opening in response to pressure of hydraulic fluid in the base cylinder suflicient to generate a differential force upon the piston in excess of that exerted by the spring.

8. A hydraulic prop in accordance with claim 7, with means comprising a handle pivotally supported on the exterior of the base head and having a cam face at the extremity thereof engaged with the end of the piston for manual release of fluid from the base cylinder to the top cylinder.

9. A hydraulic prop in accordance with claim 4, in which the last-named two conduit means comprise openings in the base extending axially thereof, and a relief valve comprising a transverse opening in the base member connected with the axial openings, a differential valve member in the transverse opening, and spring means in the valve opening for normally maintaining the valve in a closed position separating the two conduits, all for actuating the valve to interconnect the two conduits for relief of fluid over-pressure of fluid in the base cylinder.

10. A hydraulic prop in accordance with claim 4, in which the top cylinder comprises a cylindric metal tube with the top head and cross head received in the ends thereof, and the diaphragm comprising a generally cylindric member compressively received between the cylinder tube and the two heads for defining a fluid-tight space on the interior of the diaphragm member.

References Cited by the Examiner UNITED STATES PATENTS 2,973,178 2/1961 Heusner 248-354 3,012,446 12/ 1961 Heintzmann et al 12146 3,073,562 1/1963 Teb-b et al. 248-354 CLAUDE A. LE ROY, Primary Examiner. 

1. A HYDRAULIC DEVICE COMPRISING A BASE AND A BASE HEAD, A BASE CYLINDER ON THE BASE HEAD, A TOP CYLINDER TELESCOPING INTO THE BASE CYLINDER AT THE END THEREOF AWAY FROM THE BASE, A TOP HEAD ON THE TOP CYLINDER AT THE END THEREOF AWAY FROM THE BASE, A CROSS HEAD ON THE TOP CYLINDER AT THE END THEREOF ADJACENT THE BASE, A STAND PIPE EXTENDING FROM THE BASE HEAD AXIALLY THROUGH THE BASE CYLINDER AND CROSS HEAD INTO HE TOP CYLINDER, THE STAND PIPE PROVIDING FLUID COMMUNICATION BETWEEN THE BASE AND THE INTERIOR OF THE TOP CYLINDER, FLUID SEALING MEANS BETWEEN THE BASE CYLINDER AND THE TOP CYLINDER AND BETWEEN THE CROSS HEAD AND THE STAND PIPE, HYDRAULIC FLUID STORAGE MEANS ON THE INTERIOR OF THE TOP CYLINDER CONSITUTED BY A TUBULAR ELASTIC DIAPHRAGM EXTENDING PETWEEN THE TOP HEAD AND THE CROSS HEAD AND EXTENDING PERIPHERALLY ABOUT THE LONGITUDINAL AXIS OF THE TOP CYLINDER AND THE STAND PIPE, AND MEANS IN THE BASE HEAD CONNECTING THE STAND PIPE WITH THE INLET OF THE PUMP MEANS, CONDUIT MEANS CONNECTING THE OUTLET OF THE PUMP MEANS TO THE INTERIOR OF THE BASE CYLINDER, ALL FOR TRANSMITTING HYDRAULIC FLUID BETWEEN THE BASE CYLINDER AND THE STORAGE MEANS. 